Aluminum foil with improved wettability

Abstract

An aluminum foil is formed from an alloy of type AA1xxx, AA3xxx, and/or AA8xxx, which has a cold-solidified state and contains on its surface a rolling oil layer with a polyalkylene glycol or a compound containing a polyalkylene oxide structure. The aluminum foil has a thickness of 4 μm to 100 μm and can be easily coated with an electrode suspension for producing a battery film.

The invention claimed is: 
     
         1 . An aluminum foil having a thickness of 4 μm to 100 μm formed from an alloy of type AA1xxx, AA3xxx, and/or AA8xxx, which has a cold-solidified state, and which has on its surface a rolling oil layer which contains a polyalkylene glycol and/or a compound containing a polyalkylene oxide structure, wherein the alkylene group in the polyalkylene glycol or polyalkylene oxide is ethylene, propylene or butylene and the polyalkylene glycol or the compound containing a polyalkylene oxide structure is contained on a surface side of the aluminum foil in an amount of 0.01 mg/m 2  to 5 mg/m 2 , and wherein the proportion of the polyalkylene glycol or the compound containing a polyalkylene oxide structure in the rolling oil layer is up to 10 wt. % in relation to the mass of the rolling oil layer. 
     
     
         2 . The aluminum foil of  claim 1 , wherein the surface of the aluminum foil was not subjected to a corona treatment after the cold rolling. 
     
     
         3 . The aluminum foil of  claim 1 , wherein the contact angle in the drop test with NMP on the surface of the aluminum foil is less than 32°, in particular 24° to 15°, wherein the drop test as described on page  10 , lines  17  to  22  is performed with NMP instead of demineralized water. 
     
     
         4 . The aluminum foil of  claim 1 , wherein the surface of the aluminum foil in each case on a surface side has less than 1 mg/m 2  of a fatty acid and a fatty alcohol. 
     
     
         5 . The aluminum foil of  claim 1 , wherein the aluminum foil has a thickness of from 6 μm to 50 μm. 
     
     
         6 . The aluminum foil of  claim 1 , wherein the surface of the aluminum foil in each case on a surface side has less than 1 mg/m 2  of a fatty acid and/or a fatty alcohol. 
     
     
         7 . A method for producing a battery film, comprising:
 subjecting an aluminum strip of an alloy of type AA1xxx, AA3xxx, and/or AA8xxx in the presence of a cooling lubricant to a cold rolling to form an aluminum foil of a thickness of 4 μm to 100 μm, wherein the cooling lubricant is based on a mineral oil or a synthetic oil, polyalkylene glycol and/or a compound containing a polyalkylene oxide structure, wherein the alkylene group in the polyalkylene glycol or polyalkylene oxide is ethylene, propylene or butylene, and contains a fatty acid as lubricating additive in a proportion of at most 0.2 wt. % and a fatty alcohol as lubricating additive in a proportion of at most 0.4 wt. %, in relation to the mass of the cooling lubricant, and   coating the surface of the aluminum foil with an electrode coating mass,   wherein the polyalkylene glycol or the compound containing a polyalkylene oxide structure is contained on a surface side of the aluminum foil in an amount of 0.01 mg/m2 to 5 mg/m2, and   wherein the proportion of the polyalkylene glycol or the compound containing a polyalkylene oxide structure in the cooling lubricant is up to 10 wt. % in relation to the mass of the rolling oil.   
     
     
         8 . A method comprising the step of utilizing the aluminum foil of  claim 1  for producing a battery film.